Diesel fuel is the most common fuel for heavy-duty trucks. Due to its high-energy content and thus better fuel economy, diesel fuel is also widely used by passenger cars in many countries. Due, at least in part, to its economic and environmental benefits, diesel fuel is becoming increasingly more popular for passenger cars, SUV's and trucks.
Diesel engines become inoperable when the fuel temperature falls below the cloud point of the fuel, due to wax crystals forming in the fuel and plugging the fuel tank filter. The formation of wax crystals in the diesel fuel is commonly referred to as gelling. Methods for mitigating the formation of wax crystals in diesel fuel include blending, incorporating cold-flow additives, using fuel heaters and engine idling.
Cloud point and related cold-flow properties of diesel fuels is information that is not traditionally provided to the consumer. Such information may allow one to minimize or completely avoid drawbacks often associated with the above-mentioned methods. Devices for determining cloud point of diesel fuel in a vehicle fuel system are usually designed with the professional driver of diesel-powered rigs in mind. Though also usable in average consumer vehicles, these devices generally require some technical know how to install, utilize and maintain. Data collection from the device can demand active user attention and knowledge of how the device works. As such, the average non-professional user of a diesel-powered vehicle does not have access to accurate, on-the-spot information about how temperatures are affecting the diesel fuel in the vehicle's fuel system. This may result in the user taking less than effective or even ineffective preventive measures that may be quite expensive and result in a waste of fuel.